1. The Field of the Invention
The present invention relates to image processing. More specifically, the present invention relates to methods and systems for detecting the presence of objects, such as faces, within a digital image.
2. The Relevant Technology
Computer systems are increasingly used for detecting objects in digital images. For example, some computer systems are configured to examine a photographic digital image and detect the size and location of any human face within the image. At least one goal of face detection systems is to accurately detect facial features in a digital image and distinguish the facial features from other objects in the digital image. Patterns in a digital image that correspond with a face vary extensively and are highly complex, due to the variations in facial appearance, lighting, expressions, and other factors. As a result, face detection systems have become very complex.
Some common challenges in face detection systems are low detection rates and high false detection rates. For example, a face detection system may fail to detect one or more faces in a digital image. The face detection system may also falsely identify a non-face pattern in a digital image as a face. In order to improve the detection rates and the false detection rates, systems often scan an image at all possible locations and scales, resulting in a large number of sub-windows. However, this type of exhaustive search strategy can be very computationally expensive and time consuming.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.